From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422634AbWG2Fag (ORCPT ); Sat, 29 Jul 2006 01:30:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161457AbWG2Fag (ORCPT ); Sat, 29 Jul 2006 01:30:36 -0400 Received: from ns2.suse.de ([195.135.220.15]:32915 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S1161427AbWG2Faf (ORCPT ); Sat, 29 Jul 2006 01:30:35 -0400 From: Neil Brown To: "J. Bruce Fields" Date: Sat, 29 Jul 2006 15:29:33 +1000 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17610.62013.790217.817455@cse.unsw.edu.au> Cc: Andrew Morton , nfs@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH] knfsd: Fix stale file handle problem with subtree_checking. In-Reply-To: message from J. Bruce Fields on Friday July 28 References: <20060728194103.7245.patches@notabene> <1060728094255.7278@suse.de> <20060728205156.GB12183@fieldses.org> X-Mailer: VM 7.19 under Emacs 21.4.1 X-face: [Gw_3E*Gng}4rRrKRYotwlE?.2|**#s9D > It'd be great if we could deprecate subtree checking some day in the > distant future.... The first step would be to stop it from being the default (as Trond has suggested a number of times :-) How about this. I release a 1.0.10 shortly which addresses some 'portlist' related breakage and prints a nasty warning if you have neither subtree_check or no_subtree_check, but still defaults to subtree_check. Then the next release will be 1.1.0 which prints the same warning, but defaults the other way - and probably removed the warning if you include neither sync not async. That should at least get subtree_check to be used less. > > Would it be feasible to add filesystem support for some sort of > subvolume-like thing that acted like a mountpoint (in the sense that it > restricted hardlinks and renames) but that didn't require setting aside > a separate partition? I imagine that'd probably do what most people > exporting subtrees want without forcing us to do dubious tricks with > filehandles. I think it is a great idea for a 'filesystem' to support multiple independent file-trees within the one storage set, which is roughly what you are saying I think (though probably not quite). However I suspect that most people don't actually want subtrees. They just get it as the default. It isn't something that I would have implemented if I hadn't inherited the requirement, and no other OS that I know of provides that particular semantic. Maybe we should make it non-default, and then in one year, subtly break it (maybe reintroduce this bug) and see if anyone notices :-) (No, that's unethical, I wouldn't do that - really ....) NeilBrown